Тосефта к Бамидбар 5:19

He (i.e., the Kohen) would take her scroll [on which the Sotah's oath would be written] and bring it into the Ulam. A golden tablet [containing the fixed language of the oath (Num. 5:19-22)] was lodged within the wall of the Heichal, and it was visible from the Ulam. From that he looks and he writes [onto the scroll]. He neither shortens nor lengthens. He goes out and stands at the side of the Sotah. He reads and expounds and is punctilious on all the details of the parashah. And [the oath] may be pronounced in any language that she can hear (i.e., understand), in order that she knows on what account she would be drinking [the bitter waters], and about what (במה not כמה) she would be drinking, on what account she became defiled, and about what she became defiled. And he says to her, "I adjure you and it will befall you." "And this will befall you" -- this is the curse. "I adjure you" -- this is the oath. § Rabbi Meir says, [when she responds amen, amen (see Sot. 2:5), she is responding] "amen that I was not defiled," and "amen that I will not become defiled." It is not that the [bitter] waters [necessarily] inspect her immediately (see Sot. 5:1); rather, even if she becomes corrupted twenty years later, the waters will expose her [corruption], as it is said (Num. 5:15), "[the meal offering of jealousy] is a meal offering of remembrance, recalling iniquity." § [Returning to the order of the ritual,] [the Kohen] enters and writes [the oath], [then] goes out and erases it.